Add path-to-regexp for slug config

[stephenwf]

The headless static site needs to know how to extract IDs from URLs in order to map remote resources.

For example:

https://iiif.wellcomecollection.org/presentation/b30496974

This points to a IIIF Manifest, we want to be able to extract:

b30496974

And also optionally add a prefix, so that on the headless static site output it can be found at:

/manifests/wellcome-b30496974

In order to this currently we have a configuration object that must be specified by the user:

slugs:
  wellcome-manifest:
    type: Manifest
    domain: iiif.wellcomecollection.org
    prefix: /presentation/
    addedPrefix: wellcome-
    examples:
      - https://iiif.wellcomecollection.org/presentation/b30496974

An alternative might be possible with Path to regex which is fast.

Here is the current store configuration, which references the slugs config above.

  wellcomePaintings:
    type: iiif-remote
    url: https://iiif.wellcomecollection.org/presentation/collections/digitalcollections/digpaintings
    slugTemplates:
      - wellcome-manifest
      - wellcome-collection

With path-to-regex it could be:

wellcomePaintings:
  type: iiif-remote
  url: https://iiif.wellcomecollection.org/presentation/collections/digitalcollections/digpaintings
  router:
    - from: https://iiif.wellcomecollection.org/presentation/collections/{*collectionPath}
      to: /collections/{*collectionPath}

    - from: https://iiif.wellcomecollection.org/presentation/{manifestId}
      to: /manifests/wellcome-{manifestId}

That would greatly simplify both the configuration and implementation.

With this configuration, if a static page was requested:

/manifests/wellcome-b30496974

The configuration provides enough information to match it against the router.

 from: https://iiif.wellcomecollection.org/presentation/{manifestId}
+to: /manifests/wellcome-{manifestId}

And then find the original manifest to fetch:

https://iiif.wellcomecollection.org/presentation/{manifestId}

Fetching:

https://iiif.wellcomecollection.org/presentation/b30496974

It would also still have the original path to fetch the meta.json and indices.json which are not hosted at Wellcome:

/iiif/manifests/wellcome-b30496974/meta.json
/iiif/manifests/wellcome-b30496974/indices.json